Research Spotlight: Prosthetic legs gave sprinter advantage

The artificial lower limbs of double-amputee Olympic hopeful Oscar Pistorius give him a clear and major advantage over his competition, taking 10 seconds or more off what his 400-meter race time would be if his prosthesis behaved like intact limbs.

That’s the conclusion – released to the public for the first time – of human performance experts Peter Weyand of SMU and Matthew Bundle of the University of Wyoming.

The Weyand-Bundle conclusion is part of a written point-counterpoint style debate published online Nov. 19 in the Journal of Applied Physiology. Weyand and Bundle were the first two authors of the study publishing the test results acquired as part of the legal appeal process undertaken after the governing body of track and field – the International Association of Athletics Federations (IAAF) – banned Pistorius from able-bodied track competitions, including the Olympics.

In banning Pistorius, the IAAF had concluded on the basis of other data that Pistorius’ J-shaped artificial lower limbs, called “Cheetahs” by the manufacturer, gave him a competitive advantage over able-bodied competitors. But the ban subsequently was overturned on appeal to the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland.

The case has been considered groundbreaking for the eligibility of disabled athletes and the regulation of prosthetic technology in sport. Pistorius hopes to qualify for the 2012 Olympics.

The newly released conclusion from Weyand and Bundle analyzes the scientific evidence and quantifies the competitive advantage provided by Pistorius’ “Cheetah” limbs.

“Pistorius’ sprinting mechanics are anomalous, advantageous and directly attributable to how much lighter and springier his artificial limbs are. The blades enhance sprint running speeds by 15-30 percent,” says Weyand, associate professor of applied physiology and biomechanics in SMU’s Annette Caldwell Simmons School of Education and Human Development. Below the knee, Pistorius’ limbs weigh less than half as much as the limbs of an able-bodied male sprinter.